This present invention is concerned with a capping board made of plastic material reinforced with fiberglass, for supporting the ends of a plurality of electrodes immersed in an electrolytic cell, such as the cells used for electrolytically refining metal and more particularly the electrolytic refining of copper, nickel or zinc.
It is well known in the metallurgical industry to use a plurality of electrolytic cells for electrolyticly refining a metal. Usually, the metal to be refined is in the form of plates of a given thickness, which bear at their upper portion two laterally extending projections or ears used to facilitate gripping, handling and hanging of the plates on the lateral sides of each cell. These plates, which each can weigh several hundred pounds, are immersed into the cell parallel to each other and are used as anodes, cathodes or both, depending on the affinity of the metal being refined.
In order to avoid damage to the masonry or concrete forming the lateral sides of the cell during the insertion and removal of the electrodes because of their weight, it is a conventional practice to place a protecting or "capping" board made of wood on the top surfaces of the lateral sides of the cell on which the electrodes lie. The capping boards also serve to insulate the plates from each other.
These capping boards made of wood effectively protect the top portions of the lateral sides of the cells, however, they present a significant drawback in that they must frequently be replaced because they are corroded by the conventionally used acidic electrolytes or they are destroyed by the overheating that may occur in case of short circuit. Thus, for example, in almost every copper refining plant in which the electrolyte is a substantially concentrated solution of hydrochloric and sulfuric acids (20%), the wooden boards must be replaced every 10 to 20 days.
This replacement operation, which of course involves stopping of the cells during the substitution and also requires purchase and stocking of numerous replacement boards, is time consuming and very expensive in terms of inventory, equipment and maintenance staff costs, especially when one considers that the refining plants have up to 2,000 electrolytic cells. Disposal of the discarded boards by incineration or otherwise is also costly.